The OSEPP Uno R3 Plus board is the basic starter model. It serves as a great starting point to the wonderful world of Arduino. This board uses the 8-bit, AVR, RISC-based ATmega328P microcontroller from Atmel. New in R3 is added SCL/SDA pins next to AREF header and also added IOREF pin to power header. Built on the "open-source electronics prototyping platform", and compatible with existing Arduino software lilbraries.